Reversible fatigue-rejuvenation procedure and its mechanism in Hf 0.5 Zr 0.5 O 2 epitaxial films.

HfO-based ferroelectrics, such as HfZrO, arouse great attention in recent years because of their CMOS compatibility and robust nano-scale ferroelectricity. However, fatigue is one of the toughest problems for ferroelectric applications. The fatigue mechanism of HfO-based ferroelectrics is different from conventional ferroelectric materials, and research on the fatigue mechanism in HfO-based epitaxial films have been rarely reported. In this work, we fabricate 10 nm HfZrOepitaxial films and investigate the fatigue mechanism. The experimental data show that the remanent ferroelectric polarization value decreased by 50% after 10cycles. It is worth noting that the fatigued HfZrOepitaxial films can be recovered through applying electric stimulus. Combined with the temperature-dependent endurance analysis, we propose that fatigue of our HfZrOfilms comes from both phase transition between ferroelectric Pca2and antiferroelectric Pbca as well as defects generation and dipole pinned. This result offers a fundamental understanding of HfO-based film system, and could provide an important guideline for subsequent studies and future applications.